American Water Heater 300 Series Instruction Manual page 35

6. Ensure the Y connection is oriented so the air intake side of Y is
on top, see Figure 31.
7. Secure assembly to structure as shown in Figure 31 using field-
supplied metal strapping or equivalent support material.
NOTE: Ensure termination location clearance dimensions
are as shown in Figure 30, 32 and 33. When extending the
length of the 4" pipe, the added length beyond 21-1/8" must
be deducted from the maximum equivalent feet of vent pipe.
NOTE: If assembly needs to be extended to allow side wall
thickness requirement, the 2 pipes supplied in the kit may
be replaced by using same diameter, field-supplied SDR-26
PVC (D2241) pipe. Do not extend 21 1/8" (53.6 cm) dimension
more than 60" (1.5 m). See Figure 25.
Do not use field-supplied couplings to extend pipes. Air flow
restriction will occur and the heater pressure switch may
cause intermittent operation.
8. Cement heater combustion-air and vent pipes to concentric vent
termination assembly. See Figure 31 for proper pipe orientation
and attachment.
9. Operate heater through 1 heat cycle to ensure combustion-air and
vent pipes are properly connected to concentric vent termination
connections.
Figure 31
MULTI-CONCENTRIC VENT TERMINATIONS
When two or more water heaters are direct vented with concentric
vent terminations near each other, each water heater must be
individually vented. NEVER common vent this water heater. When
two or more water heaters are direct vented using concentric vent
terminations, the water heaters may be vented as shown in Figure
32 and Figure 33.
Figure 32 CONCENTRIC VENT TERMINATIONS FOR
HORIZONTAL DIRECT VENTING
Figure 33 CONCENTRIC VENT TERMINATIONS FOR
VERTICAL DIRECT VENTING THROUGH A ROOF
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